class Solution {
public:
    long long flowerGame(int n, int m) {
        long long oddn = (n + 1) / 2; long long oddm = (m + 1) / 2;
        long long even = n / 2; long long evem = m / 2;
        long long ans = (oddn * evem) + (oddm * even);
        return ans;
    }
};


// 1 3     2
// 1       2